Compass.



R. HUNTINGTON.

COMPASS.

APPLICATIONv FILED MAR,- 22, L942. 1,215,808. Patented Feb. 13,1917. ZSHEETS-SHEET lv 1 a z 6 z 1 R. B. mm W fl g? R. HUNTINGTON.

COMPASS.

APPLICATION FILED ma 22. m2.

1,21 5,808. Patented Feb. 13, 1917.

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ROBERT HUNTINGTON, 015 SOUTH MEDFOED, MASSACHUSETTS.

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Specification of Letters JPatent.

Patented Feb. 113, Edit.

Application filed march 22, 1912. Serial Ito. 685,645.

has'for its particular object the correcting or overcoming of the effect of local, permanent magnetism due to the metal used in ship constructing.

As is well known, the eflect of polar magnetism induces certain magnetic currents through the frame of a ship, causing it, in time, to assume some 'of the properties of a permanent magnet. As such the metal work of the vessel will have a certain influence upon the compass and under such influence the needle of the latter will vbe somewhat drawn from its true course.

' The 'term sub-permanent magnetism has been given to this force and the deflection of the needle is known as deviation. When the sub-permanent magnetism of the vessel is equally distributed along the keel, its efiect upon the needle is zero when the ship is headed magnetic north or south but should the ship be headed magnetic east orwest, the efleet of this local attraction will cause repulsion of the north end and attraction of the south end of the needle from its proper course, causing westerly or easterly deviation, respectively.

When this sub-permanent magnetism is unequally distributed along the keel of the vessel .as is generally the case, due to the unequal distribution of the metal which induces it, the point of non-attraction (the zero above) ;lies in a plane slightly to the right or left, as the particular case may be) of the line of the keel, andthe line of no deviation is slightly deflected from the north and south magnetic course.

To overcome these difliculties, I have invented a new form of compass, which greatly minimizes the deviation of the needle and have added what I will call a sub-permanent magnetism adjuster, the object of the latter being to correct the unequal eiiect of localattraction noted in the preceding paragraph.

As this sub-permanent magnetism adjuster is applicable to all form s of cornpasses, I do not claim it broadly herein but make it the subject of a separate application filed concurrently herewith.

In the drawings which accompany and form part of this specification: Figure 1 is a vertical central section of my compass box with adjuster attached.

Fig. 2 is a plan'view of my compass-dial partly broken away to show magnets underneath.

Fig. 3 is a diagram similar to Fig. 2. Fig. 4 is a plan of my adjuster, and Fig. 5 is an edge view of one end of same.

The compass-box 1, provided with the ordinary pintles 2, 2 for mounting on a binnacle has aiglass cover 3 hermetically sealed to the box 1 so that the spirits or other liquid with which the latter is filled may not escape. The needle-pivot 4 is adjustably mounted on top of this cover 3 and the compass-dial 5 is buoyed, as by asuitable float 6, so as to make its pressure within the liquid upward against said pivot 4. This method of pivoting the compass-dial I believe to be entirely new.

Underneath the dial 5, and secured thereto I place one or more pairs of permanent magnets 7, 8, their magnetic axis being the N.-S. line of dial 5.

The fundamental idea of this invention consists in separating these magnets, one of a pair being placed near each outer edge of the dial 5 along the N.S. line, with the north seeking end of each toward the N. end of said line.

My objects in providingthe dial with To still further lessen the deviation curves above described, ll prefer to secure to the dial small side magnets 9, 9 mounted near the east and west points of the dial 5, the polarities of which are indicated by ends respectively as in the mag- 15 serve to frictionally lock the rod 14 at any desired height below the box 1.

Slidably and rotatably mounted on the rod 14 is the boss 16 of a fiber, paper or rubber tube 17, the latter being adapted to receive one or more magnets 18, which may be held in place by set-screws 19, the latter working through grooves 20 in the tube 17 to permit sliding of the magnets 18 within the same. By means of the set screws 21 the tube 17 may be secured at any transverse position onthe rod 14 and also at any ver- ,tical angle which the dip of the magnetic needle may render necessary.

I thus provide a universally adjustable sub-permanent magnetism adjuster, within the limits that practice has shown to be necessary.

The proper adjustment of the magnets 18 once found, they need not be changed unless there is cause to believe that the inequality of the sub-permanent magnetism of the vessel has been changed.

, What I therefore claim cure by Letters Patent is:

1. In combination, a. compass box, a dial pivotally mounted therein, a, pair ofmain magnets mounted on said dial at opposite sides thereof, a pair of auxiliary magnets mounted on said dial opposite to each other but not to the main magnets, a mount for a pair of corrective magnets pivotally hung from said compass box, and a corrective and desire to semagnet adjustable along each end of said mount.

2. In comblnation, a compass box, a dial pivotally mounted therein, setsof magnets 'mounted on said dial at opposite sides thereof, auxiliary magnets mounted on said dial opposite to each other but not to the sets of magnets, a mount for a pair of corrective magnets pivotally hung from said compass box, and a corrective magnet adjustable along each end of said mount.

- 3. In combination, a compass box, a dial pivotally mounted therein, a pair of. main magnets mounted on said dial at opposite sides thereof, sets of magnets disposed on opposite sides of each main magnet, auxiliary magnets mounted. on said dial opposite sides thereof, a pair of auxiliary magnets mounted on said dial opposite to each other but not to the main magnets, a frame pivotally hung from said compass box, a rod adjustable in said frame, a. slide adjustable along said rod, and a corrective magnet adjustable on each end of said slide.

5. In combination witha compass box providing amounting for a pivoted compass, a frame, means for supporting said frame in pivotal relation to the pivot of the compass, a rod mounted in said frame for vertical adjustment in the plane of the pivot, a transverse member mounted on said rod and slidable thereon, a magnet adjustably mounted on each end of said transverse member, and means whereby said magnets may be adjusted in lateral relation to said rod.

6. In combination witha compass box, a depending frame, a horizontal rod mounted in said frame for vertical adjustment therein, a transverse member mounted on said rod and slidable thereon, means for locking said member on saidrod, a magnet on each end of said member and means whereby said magnets may be adjusted in lateral relation to said rod.

7. In combination with a comp'ss box, a depending frame having a pair of oppositely disposed lateral slit arms, a rod having-its ends mounted in said slits, means for clamping said rod ends within said slits, a tube transversely mounted on said rod and slidable thereon, means for locking said tube on said rod, a magnet on each end of said tube, and means whereby said magnets may be adjusted in lateral relation to said rod.

8. In combination with a compass, a vertically adjustable support, a member adjustable laterally on said support, and a magnet adjustable on each end of saidmember.

pivotally hung from said box, a magnet carrying member, means for" supporting the same with relation to said frame whereby the member is vertically, laterally and transversely adjustable, and a magnet independ-v ently adjustable along each end of said member.

10. In combination, a compass box, having a threaded boss on its under face, a magnet support pivotally hung from said boss, and a pivotal connection between said boss and support consisting of a screw in said support and threaded into said boss, said screw permitting a limited vertical adjustment of the support relative to the combearing, and a magnet adjustably mounted 1:) pass box and permitting swinging moveon each end of said slide. ment of said support about the pivot as an In testimony whereof I affix my signature axis, and means for holding said vertical in presence of two witnesses.

5 adjustment.

i T T 11. In combination with a compass box, ROBERT HUhTIhGTGN a frame pivotally connected therewith, a rod Witnesses: adjustable in said frame, a bearing adjust- R. B. ELLMs,

able'on said rod, a slide adjustable in said VICTORIA LONDEN. 

